ESF- Chapter 18

Section

Question

Answer

Manufactured gas

A form of gaseous fuel derived primarily from coal.this manufactured gas was desirable as a way to provide lighting to customers delivered through dedicated pipes to lamps and also directly to customer locations for internal use. Eventually, lighting applications largely migrated to cheaper and safer electricity and, as a result, the use of manufactured gas diminished.

Methane (CH4)

methane is a powerful greenhouse gas, Which has the equivalent heating effect (Global Warming Potential, or GWP) of 86 times that of carbon dioxide over a 20 year timeframe and 34 times over 100 year timeframe.

Associated gas

natural gas that emerges from oil wells that emerges during oil production. The proportion of oil and gas are highly dependent on the underlying geological conditions of the reservoir.

Flaring

A method to manage associate gas by burning of the methane in flare stack.

Therms

Unit to measures energy in natural gas, equivalent of 100,000 Btu

Unconventional gas

Natural gas deposits that are available in may other geological formations that have trapped hydrocarbon, including coal seams and shale rocks

Tight gas

The type of gas that is trapped in a low permeability source rock deep underground such as sandstone or limestone. Because this gas is not freely flowing, some methods have been developed to liberate the gas from the rock, called well stimulation. The most common method for this is using high-pressure water injection to break up the source rock, also called hydraulic fracturing.

Hydraulic fracturing

One type of well stimulations done through high pressure water injection to break up the source rock to liberate tight gas from the rock.

Shale gas

natural gas trapped in even deeper and denser shale source rock, and obtaining commercial quantities of natural gas requires even higher amounts of stimulation of the rock through hydraulic fracturing.

Horizontal drilling

drilling laterally across the source rock. This is a type of drilling technique to make the extraction of shale gas cost effective.

Coal-bed methane (CBM)

shallower source of natural gas is found co-located with coal deposits, where the natural decomposition of organic material over time created some amount of methane that remains trapped inside the deposit.

Initial production (IP)

the average amount of gas produced over a specific time frame of a well. Usually refers to the first 24 months.

Landfill gas

he methane that is captured from the decomposition of material in waste landfills

Biogas

An important source of natural gas, created by breaking the organic matter down with anaerobic bacteria in a digester creating methane that can be used for thermal energy purposes

Digester

air tight tanks in which biogas is created by breaking the organic matter down with anaerobic bacteria

Gas Initially In Place (GIIP)

Estimates the total amount of gas in the reservoir based on seismic data and exploratory well experience

Recovery factor

% of the total GIIP ultimately obtainable

Casing

cement liners intended to protect agains contamination of the surrounding soil and water

Produced water

water extracted from the well in shale gas production

Raw gas

gas that comes out of a well including a number of hydrocarbons and other contaminations along with the methane.

Pipeline-quality natural gas

at least 97% pure methane, with low amount of carbon dioxide or other sulfides that would corrode the pipeline infrastructure or % health risks to workers

Dry gas

gas that has very low concentrations of other hydrocarbons and also requires less processing in order to bring it up to pipeline quality natural gas

Wet gas

liquid-rich gas that has a high concentration of NGLs and condensate and a result it has a relatively high energy content per volume

Compressed Natural Gas (CNG)

A form of natural gas under pressure. Natural gas transported using vehicles is usually compressed in tanks and trucks.

City Gate

A point where natural gas transmissions ends and enter the distribution infrastructure

Federal Energy Regulatory Commission (FERC)

A federal body responsible for the oversight of pipelines operation particularly when crossing state and international boundaries.

Local Distribution Companies (LDC)

The entity that manages the natural gas distribution. It range from the very small to very large often jointly owned or related entities to electricity distribution companies in the same geography

Fugitive emissions

A number of other emissions emitted in the natural gas supply chain

Volatile organic compounds (VOCs)

a class of organic chemicals such as benzene that can have significant health effect on local populations.

Global Warming Potential (GWP)

the impact of emissions of a gas compare to an equivalent mass of CO2

Heating Degree Days (HDD)

measures how much heating load is required .

Stranded gas

natural gas that can not be brought to the market due to lack of geographic connection or capital to establish pipelines facilities.

Liquified natural gas (LNG)

Liquid natural gas that is obtained through cooling down the natural gas down to the temperature at which it becomes liquid or -162 degree Celcius (-260 degree Fahrenheit). LNG can be more cost effectively transported in special ships over long ocean routes.

Halliburton loophole

The exemption of hydraulic fracturing from compliance with federal law regulating water contaminations in the US( Clean Water Act and the Safe Drinking Water Act).

Induced seismicity

seismic activity induced when water injections often through produced water injections into disposal wells, deep underground.